/**
 *@file hello.cpp
 *@auhor Ye Jichuan
 *@Date Fri Sep 17 10:40 2021
 *
 *@brief A demo program for learning.
 *
 */
#include<iostream>

int main(int argc,char* argv[])
/**
 *main function.
 *
 *@param argc number of shell parmeters.
 *@param argv strings for all parameters.
 *
 *@return system signals.
 */
{
  /// just a demo.
  std::cout << "Hello World!" << std::endl;
  return 0;
};
